I develop a new class of
models of spiking neurons that combines
computational efficiency of integrate-and-fire and resonate-and-fire
models and biological plausibility and versatility of Hodgkin-Huxley
type models.

Find the fake!
In this figure, one column is an in vitro recording of rat pyramidal
neuron (layer 5,
motor cortex) in response to pulses of injected current of various
amplitudes, the other column is a simulation of the simple model

100v'=0.7(v+60)(v+40)-u+I,

u'=0.03(-2(v+60)-u),

if v>+35 mV
(peak of spike),
then
reset: v := -50 mV, u := u+100

Can you determine which is the real neuron which is
the fake? (Hint: the real one is noisier.)

I develop large-scale
models of the brain having microcircuitry
of the mammalian
thalamo-cortical system.

On October 27, 2005 I finished simulation of a model that has the size
of the human brain. The model has 100,000,000,000 neurons (hundred
billion or 10^11) and almost 1,000,000,000,000,000 (one quadrillion or
10^15) synapses. It represents 300x300 mm^2 of mammalian
thalamo-cortical surface, specific, non-specific, and reticular
thalamic nuclei, and spiking neurons with firing properties
corresponding to those recorded in the mammalian brain. (Even if
the model had only 1000 neurons, it would still be one of the most
detailed models ever simulated.)

The model
exhibited alpha and gamma rhythms, moving clusters of neurons in up-
and down-states, and other interesting phenomena (watch a 25M .avi or .mov
movie).

One second of simulation took 50 days on a beowulf cluster of 27
processors (3GHz each). Why did I do that?

You can read more about this model in my 2008 PNAS paper and download some interesting (but long) movies of the spiking activity of the human brain model.

This research has a more ambitious goal than the the Blue Brain Project conducted by IBM and EPFL (Lausanne, Switzerland). The Blue Brain Project builds a small part of the brain that represents a cortical column, though to a much greater detail than the models I develop. In contrast, my goal is a large-scale biologically acurate computer model of the whole human brain. At present, it has only cortex and thalamus; other subcortical structures, including hippocampus, cerebellum, basal ganglia, etc., will be added later. Spiking models of neurons in these structures have already being developed and fine-tuned.